21436902 has 36 divisors (see below), whose sum is σ = 49034700. Its totient is φ = 6767496.

The previous prime is 21436873. The next prime is 21436927. The reversal of 21436902 is 20963412.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4849 + ... + 8147.

It is an arithmetic number, because the mean of its divisors is an integer number (1362075).

Almost surely, 2^21436902 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21436902, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24517350).

21436902 is an abundant number, since it is smaller than the sum of its proper divisors (27597798).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21436902 is a wasteful number, since it uses less digits than its factorization.

21436902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3345 (or 3323 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 21436902 is about 4630.0002159827. Note that the first 3 decimals coincide. The cubic root of 21436902 is about 277.7926010341.

It can be divided in two parts, 2143 and 6902, that added together give a triangular number (9045 = T₁₃₄).

The spelling of 21436902 in words is "twenty-one million, four hundred thirty-six thousand, nine hundred two".